> [...] using standard GAS and GLD (2.6 with AXP patches)
Here's the main problem. The 2.6+ gas didn't know about 21164 HW
instructions at all (the -m switch was not connected to anything)
and furthermore got the 21064 HW instructions wrong.
The Alpha assembler has subsequently been rewritten. You'll need
a resonably recent snapshot of gas to see it, though. An unofficial
copy of it can be found at
ftp://atheist.tamu.edu/pub/richard/gas-960707.tar.gz
r~